Optimized first room

The main goal of this short tutorial is to give you the keys to
building a clean and FPS optimized room with Radiant.

Before you start

As the goal is to have the most FPS friendly map possible, we first need
to take care of some settings. The caulk shader is one of the
most important here; when adding a new brush, it should always be textured
with the caulk shader in order to avoid useless drawnings made by the engine.

Setting it as the default texture to apply is a good way to avoid having
to think about it, in NetRadiant, open the Preferences
menu, click the Settings -> Brush entry and check the
Always use caulk for new brushes checkbox.

Almost done. when clipping a brush, the last selected texture is applied
to the new faces of the brush. In order to avoid this and automatically apply
the caulk texture, we need to set another option up: select the Clipper
entry of the Preferences menu and check the Clipper tool uses
caulk.

It's all about 45 degrees

There is nothing much to say about building an optimized room,
the only good thing to know is: avoid the hollow tool and join
your brushes with a 45 degrees angle to get the most of a FPS-friendly rendering.

So, here is how to build such a room.
At first, after drawning a squared brush, select the Clipper tool.
We will only have to use the 2-points clipping technique: select the view which
suits your need (the Y,Z view in our case) and click on the far
bottom edge to place the 1st point of clipping, then place the 2nd point at
exactly 45 degrees. For a 32 units height brush, it's a 4 units offset:

Still in the same view, do the same on the opposite side of the brush
then change to the X,Z view and repeat the process on these
two sides of the brush:

When the 4 sides have been clipped, we can now duplicate our brush:
press the SPACE bar and use the
Z-axis Flip tool to put the side upside-down:

Now if you rotate this brush with the Y-axis Flip tool,
you will have a perpendicular brush, suitable for a wall:

Repeat the process until you get all your floor, your ceil and
your 4 walls. Congrats! You just have done the perfect room :)

As an end note, you may notice that using the 45 degrees edges
allows us to restrict the texturing process to visible surfaces only,
and thus making the brush FPS-friendly. The example room is available
as tuto_optimized_first_room.map.